Resonating, modulating, and projecting of sound animated by electrical means



March 1, 1932. c. A. VOLF. JR 1,847,284

RESONATING, MODULATING, AND PROJECTING OF SOUND ANIMATED BY ELECTRICAL MEANS Filed Nov. 2, 1929 3 Sheets-Sheet 1 March 1, 1932. g A, \IOLF JR 1,847,284

RESONATING. MODULATING, AND PROJECTING OF SOUND ANIMATED BY ELECTRICAL MEANS Filed Nov. 2, 1929 3 Sheets-Sheet 2 E) INVENTOR ATTORNEYS March 1, 1932. c, VQLFY JR 1,847,284

RESONATING, MODULATING, AND PROJECTING OF SOUND ANIMATED BY ELECTRICAL MEANS Filed Nov. 2, 1929 3 Sheets-$heet 3 x) INVENTOR (Vi/2'5 22m .17 %*//'Jir BY QM M ATTORNEYS.

Patented Mar. 1, 1932 UNITED STATES PATENT ore-lea CHRISTIAN A. VOLF, JR, OF WEEHAWKEN, NEW JERSEY, ASSIGNOB TO MURRAY '1.

QUIGG, OF NEW YORK, N. Y.

BESONATING, MODULATING, AND PBOJ'ECTING OF SOUND ANIMATED BY ELECTRICAL MEANS Application filed November 2, 1929. Serial No. 404,314. I

This invention relates to sound resonating and sound projecting devices and more particularly to a resonating device of the uni-directional type particularly adapted for use in auditoriums, theatres and the like, in

which sound is to be projected or emitted from a stage or platform mainly in one general direction. Y

The present invention is an improvement on the inventions illustrated and described in my applications Ser. No. 323,019, filed December 1, 1928, and Ser. No. 340,926, filed February 18 1929, in both of which the sound waves are irected on to the surface of a. liquid and emitted substantially in every direction or, in other words, in the direction of all the points of the compass.

In the preferred form of the present invention sound Waves which are set up by elec trical means placed directly over an opening in the top of a container are directed against a board suspended within the container, the board supporting suitable resonating tubes. The sound waves are deflected by the board, thereby setting up an echo, and the waves, together with the echo reinforcing and accompanying them, are resonated by the tubes and are discharged by the tubes upon a surface of water which vibrates in harmony with the sound waves thus received upon its surface. The impact of the sound waves on the surface of the water sets up a second echo which reinforces and accompanies the waves of which it is an echo. The waves so reinforced are carried by the vibration of the surface of the water along the surface of the water, remaining on the surface of the water to the margin most distant from the 'pointof impact, at which point they are discharged in a sin le direction. By the means which will be ereinafter more particularly described, undesired-electrical and mechanical sounds known as distortions are prevented or inhibited, and the desired vocal or other musical frequencies are resonated or modulated and are mingled and directed at a predetermined angle into an auditorium, whether indoors or outdoors, so that'the sound vibrations are distributed evenly to all parts of the auditorium, without reverberation from the walls and without 2 interference, clashing, or neutralization in mid-air of sound waves deflected from walls and other obstacles.

One object of my invention is to resonate and modulate voice and other musical frequencies by means of air columns appropriate to the several frequencies in order to improve the quality of musical tones and human voice transmitted by electrical means, whether from microphones, records or other sound producing means.

Another object of my invention is to mingle different sound waves set up by simultaneous frequencies, thus preventing waves of low frequency from escaping into an auditorium at one angle to the auditors while the waves of high frequencies escape at another causing a predominance of low tones in one part of the auditorium and high tones in another, as is the case with the horns and cones now 'generally in use, and by said mingling of thus reinforcing and clarifying the sound before it is discharged into the auditorium 01' atmosphere.

Another object of my invention is to cause two predetermined echoes, each of which accompanies the sound of which it is an echo, before the sound is discharged into the auditorium in order to prevent uncontrolled echoes set up by the walls and obstacles within the auditorium which would cause distortion. It is known in the science of acoustics that the first and second deflections of a sound wave causes an echo, but at the third angle of deflection no echo is set up and the sound wave is neutralized.

Another object of my invention is the projection or discharge of sound waves into an auditorium at a controlled angle in such a way that sound waves of varying length each move at the same angle from their common point of departure, or, in other words, all waves move in a path of the same character, thus preventing distortion set up by resonance and reverberation of walls and obstacles and the neutralization of sound waves by the collision in mid-air of waves of the same pitch which have been deflected from oppos te walls, whichjj causes what are known as"de'ad spots. y Another object of my invention is theehmination in large measure of mechanical and electrical distortion inherent in sound repro duction by electrical means from the aggregate of sound waves before the said waves are discharged into the auditorium or atmosphere.

Various other objects ofmy invention will be apparent from the following detailed dcscription ofthe preferred embodiment of the invention. 7 1

Myinvention is based upon thefact, amon other things, that still water or other liquid with vibrating qualities approximating those of water, whenemployed in the manner described in the applications above referred to, vibrates in harmony with musical notes and I tones of the human voiceon'ly, and by such 'v'i- 25 bration transmits sound tour in contact with its surface. Vibrations caused by waves of lower frequency penetrate to a varying depth,

up to four inches, but all vibrations are most concentrated atthe point of least depth. Thus sound waves of varying frequency strikin water of a depth offour or more inches wi l vibrate the water and vibrations will animate and. recreate identicalsound waves at the margin of, the water. If the margin ofthc water at one point is more shallow-than at all the, other points of the margin, the greatest intensity of vibration will occur at that point. It is known also that sound waves are trans mitted, at least, b rolling over or passing overthe surface 0 the water or other liquid outwardly as described in the applications above referred to, always seeking as a point of departure the margin of the liquid farthest from the point of original vibration.

The various features of my invention are illustrated in the accompanying drawings showing the invention in its prefer-redembodiment' and a modification thereof, inwhich I .Fig. 1 is a view in elevation, partly in section, of a device embodying my invention Fig. 2 is a'cross section on the line 22 of gfi I 1 board; v Fig. 4 is aview inperspective of the device shown in Fig. 1; t

Fig. 5 is a detailed sectional view showing the container and the water tank;

Fig. 6 shows in perspective a modified form especially adapted for use out-of-doors; and t Fig. 7 is a view inelevation, partly sec-.

tional, of the device as shown in Fig. 6.

Referring more particularly to thedraw- 5 ings, the numeral 2 indicates a casing rectan-,

gular in shape and open at the lower end.

3 is a detail of the structure of the tube The casing is preferably made of heavy resonating material, such as five-ply wood veneer, free from knots or other imperfections. To the sides of the casing are preferablytscrewed triangular pieces 15, and thin blotting paper 15 is referably inserted between the edges of tlie sides and the sides of the top where these are joined which serves to improvethc resonating qualities of the casing. The pieces 15 reinforce the frame of the casing and give the interior of the easing a somewhat octagonal shape, consisting of four long sides and four short sides. The short sides resonate in harmony with the high frequencies and thus dispel the clash of such frequencies at sharp corners.

Three sides of the bottom of the casing are placed flush with three sides of the top of a li uid container 4. The liquid container is pre erably made of, or lined with, glass, metal or other material adapted for holding water or other liquid without deterioration. One side of the liquid container protrudes beyond one side of the casing, and on this side the inside wall of the container forms an angle of less than 45 degrees with the floor of the container. The other sides of the container are at right angles withthe floor thereof. The liquid employed in the container is I preferably water, although anyfit'her liquid having the vibrating qualities of water may be used. The depth of the liquid in the con- 'tainer is 4: inches or more.

The sound waves may be generated by any instrument suitable for animating sound "waves transmitted from a record, microphone or other similar device, and adequate'for the use intended, the said instrument being no part of this invention. This device may be housedin. a "separate casing 6, the sound waves passing through a small amplifying coneor horn 8 serving to guide the sound waves to within the casing 2 through anaper- :"ture 3 of appropriate size in the top thereof whence they come in contact with and are deflected by a tube board 12. The tube board 12 supports a series of resonating tubes 10. Each tube is suspended in an opening corresponding to the size of the tube and held by means of a copper wire or ring, 7, as shown in Fig. 2, for example, surrounding the tube above the board, forming a seat for the tube and holding it in the desired downward direction.

The board 12 is preferably made of nonre s onant and non-absorbent material 'of sufficient thickness and strength to hold the weight of the'desired number of tubes. A

detail of the construction of the board is shown in Fig.3, indicating two layers 20 of balrelite separated by a layer 21 of celotex and held firmly together by a bolt orclamp 22 at each of the fourcorners, to which is attached a ring 23 by which the board is are set up before the sound came suspended from the top' 'of the chains 14. y

The sound waves deflected by "the board find. their escape through the tubes, each tube resonating the {sound frequencies forwhich it is designed andadapted. Mechanical and electrical noises set up by the generating means 6 or by distortion of sound which may occur in the casing are not I resonated and are dissipated by the resistance ofcasing and the tubes. I V I The sound waves emitted from the tubes vibrate the water, the lower frequencies vibrat-ing the water to a depth of about 4 inches.

The vibrations are transmitted through the water to the points of least depth where the vibrations are most intense, namely, at-the margin of the water on the side having the sloped interior18. The intensity of the vibrations there communicate the vibrations to the air. The sound waves so setup, together with the sound waves which have rolledover thesurface of the water, make their escape uponthe lines of least resistance, namely, up

the. sloped angle 18 and are fromthere emitted into the auditorium in the desired direct-ion, all't-he waves taking'a path of the samecharacteristic. Since the sound waves of varying frequency which leave the sound animatinginstrument at various angles are all directed to the" surface of the water b the resonating tubes, the

" waves of high ant low frequency mingle in the vibration of the water and the mingled vibrations cause the proper blending of the high and low frequencies which, as above explained, leave the instrument in a pathof-the same characteristic.

The contact of the sound waves emitted from the resonating tubes with the surface of the water creates echoes which immediately clarify, reinforce and accom any the waves of which they are echoes. T us by the tube board 12 and the water 16, two predetermined echoes, each of which clarifies, reinforces and accompanies the wave of which it man echo,

to the auditorium. v I

By determining the path of the sound waves emitted from my device, the projection ofthis path may be directed through the length of the auditorium to the wall most dista'nt from the source of the-sound; By reason of the. fact that the sound waves have been deflected twice within the device, contact with the walls of the auditorium will make a third angle of deflection which will neutralf. ize the sound. By placing a heavy curtain or motion picture screen in front of the casing, but not in front of the liquid container, so"

that sound waves escapingdirectlyfrom the outside of the bornor cone 8 are trapped, the only sound projected'into the auditorium is that which comes directly from the water surface, andthe entire auditorium is filled with waves are emitted soundroming directly from the water surface, thereby doing away with dependence upon the deflection of sound waves from walls in order-to fill the auditorium, and also the creation by such deflection of distortion, and furthermore obviating the collision of identical pitched notes which causes their neutralization and creates what are known as dead spots.

It will be apparent to those skilled in the art that any number of resonating tubes may be employed, limited only by the size of the casing which, in turn, is limited by the power of the sound animating means to force the air waveslthrou h the tubesand thecasing.

If the device is to be employed exclusively for the resonation,.modulation and rojection of human speech, the number 0 tubes employed may be, for exam 1e, 24-the tubes being of different sizes-t e'longest being about 24 inches in length and the smallest of an inch in length, the intermediate lengths being proportionate in size and number to maintain the proper balance. In providing for the resonation, modulation and projection of the human voice and music it is desirable to use a larger number of tubes covering a wider range of tone frequencies, say, forexample, 82 tubes; each being a quarter note apart. Provision is preferably made in the tube board to separate, as far aspossible,

tubes closely related to one another in the scale, so that the waves emitted from tubes closely related to one another in the scale 6', one on top of thecasing, and another fastened insidethefcasing to a special board on the outside of the casing. It is known that a cone diaphragm discharges sound waves not only from the inside but from the outside of the cone. Waves discharged from the outsideof thecone 8" of the animating means 6',

shown inside the casing in Fig. 7, are resonated'by the tubes 10' and partly by the smaller tubes directly above the cone, as shown in Fig. 7. The sound frequencies so resonated vibrate the water and are discharged from the device as heretofore described. The

sound'waves discharged from the inside of the cone go directly into the atmosphere without resonation, modulation or control of their direction.

It is to be understood that various changes or modulations may be made in the forms of my invention above described, as will be apparent to those skilled in the art, without departing from the spirit or the scope of the invention as defined in the claims.

Having thus described my invention, what is claimed as new is 1. A sound resonating and modulating device comprising a casing, sound generating means connected thereto, a pluralit of tubes within said casing, a container for liquid positioned to receive sound waves from said tubes and a sound-emitting outlet communicating with the surface of said liquid so positioned as to emit sound waves outwardly in substantially a single direction.

, 2. A sound resonating and modulating de-. vice comprising a casing, sound generating vice comprising a casing, sound generating means connected thereto, a plurality of tubes vice comprising a casing,

- substantially vertically arranged within the casing and a container for liquid below the said tubes having an angularly disposed sound outlet for sending and projecting unidirectional sound waves in the desired path.

. 4. A sound resonating and modulating de vice comprising a resonating casing. sound generating means connected to the saidcasing,

.a series of resonating tubes mounted within said casing, said casing and tubes being adapted to resonate sound waves within the range of audible frequency, a container for liquidpositioned to receive sound waves from the said tubes to cause vibration of the said liquid in response to the impinging sound wavesand an angularly disposed outlet above the said liquid permitting sound waves emitted to travel outwardly therefrom in a single direction at an angle within forty-five degrees with the horizontal, thus permitting substantially all the energy of sound to be utilized in the desired direction for audition.

5. A sound resonating and modulating de vice comprising a resonating casinghavinginterior corners, means for barring said corners to prevent interference or clashingof high frequency vibrations, a series of resonating tubes mounted within said casing, a. container for liquid disposed below said tubes to receive sound waves therefrom, and an outlet having substantially parallel sides for emitting sound waves from above the surface of the liquid in substantially a single direction to permit substantially all the sound waves to be utilized for audition in the desired path.

6. A sound resonating and modulating dea plurality of resonating tubes mounted therein to provide a plurality of air columns adapted to resonate appropriate sound frequencies, sound generating means associated with said casing to provide sound frequencies which may be resonated by the said air columns appropri' ate thereto, a liquid surface positioned to receive resonated waves from the said tubes and means to permit the escape of sound waves from the surface of the liquid in the desired direction for audition.

7. A sound resonating and modulating device comprising a casing, a plurality of resonating tubes mounted therein, sound generating means connected to the said casing, whereby the several frequencies set up by the sound generating means may be resonated by air columns in the appropriate resonating tubes, means for positioning a liquid beneath the tubes to receive the resonated waves from the said tubes, whereby the scveral frequencies of different sound waves simultaneously set up by the said sound generating means may mingle and blend on the surface of the liquid from which the frequencies or waves may be projected at the margin of the said liquid in a single predetermined direction.

8. A sound resonating and modulating device comprising a casing, a plurality of resonatin tubes mounted within the casing, sonn generating means connected to the said casing so as to cause frequencies set up by the sound generating means to be resonated by air columns in the appropriate resonating tubes, means for positioning a liquid below the said tubes to receive resonated waves therefrom, whereby sound generated by electrical and mechanical means accompanying the said frequencies may be dissipated by the dampenin effect or resistance of the casing and the tubes to prevent the commonly called distortion, and means to permit escape of the resonated sound waves from the surface of the liquid in a single predetermined direction for audition.

9. A sound resonating and modulating device comprising a casing. sound generating means connected therewith, a tube board and a plurality of tubes mounted thereon in the said casing, a liquid container positioned to receive sound waves set up by the sound generating means and resonated by said tubes. the said sound waves from the said sound enerating meansbeing deflected by the tube ard and setting up predetermined echoes which accompany, clarify and reinforce the sound waves of which they are echoes, whereby the sound waves so reinforced are resonated by the tubes and projected upon the surface of the said liquid, the contact with the liquid setting up another predetermined echo acompanying, clarifying and reinforcing the sound wave of which it is the echo, and means for permitting projection of the sound waves thus reinforced into an auditorium in a single predetermined direction,

ing to permit the vibration thereof, whereby musical frequencies are amplified and distortions or undesired vfrequencies are dampened, a container for liquid below the said tubes to receive sound waves transmitted by the resonating oi the air columns within the tubes and an outlet from the said container adapted to emit sound waves in the desired path of audition.

11. A sound resonating and modulating device comprising a casing rectangular in shape and open at the lower end, the sides of the casing having attached thereto triangular sections of material adapted to prevent distortion of sound within the casing, the positioning of the said triangular sections giving to the interior of the casing a modified octagonal form, and sound deadening means between the abutting edges of the casing'to improve the resonating qualities of the said casing.

12-. A sound resonating and modulating device, comprising a casing, sound generating means in the upper part of the casing, a

plurality of vertically disposed, open-ended resonating tubes positioned directly below said sound generating means, a container for liquid positioned directly below the lower ends of the several resonating tubes, and a sound emitting outlet communicating with Y means in the upper part of the casin I rality of vertically rality of vertically disposed, open-ended reso-- the surface of the liquid so as to em1t resonated sound waves in direction. 1 1 p '13. A sound resonating and modulating device, comprising a casing, sound generating a pludisposed, open-en ed resonut-ing tubes positioned directly below said sound generating means, a second sound generating means positioned in one of the side walls of the casing, for projecting sound waves directly outwardly therefrom, a container for liquid positioned directly below the lower ends of the several resonating tubes, and a sound emitting outlet communicating with the surface of the liquid so as to emit substantially a single resonated sound wavesin substantially a single direction.. g 00' a device comprising a casing, sound generating 14. A sound-resonating and modulating crating means positioned in one sideoi said casing, a second set of vertically dis osed, open-ended resonating tubes associate with said second sound generating means, a container for liquid ositioned directly below the lower ends of t e several resonating tubes, and a sound emitting outlet communicating with the surface of the liquid so as to emit resonated sound waves in substantially a single direction. i

15. A sound resonating and modulating device, comprising a casing, sound generating means in the upper part of the casing, a plurality of vertical y disposed, open-ended resonating tubes positioned directly below said sound generating means, a second sound generating means positioned in one s1 said casing, a second set of vertically d15- posed, open-ended resonating tubes associated with said second sound generating means, said second sound generating means serving to project sound waves into said second set of resonating tubes, and also laterally death and directly outwardly of the casing, a cOn-- loo means in the upper part of the casing, a plunating tubes positioned directly below said sound generating means, a second sound gen- 

